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Finding the Fourth Proportional to 621.72, 857.69 and 385.60

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Solution

The fourth proportional to 621.72, 857.69 and 385.60 is: 531.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.72 : 857.69 = 385.60 : x
  2. Step 2: Convert to fraction form
    621.72/857.69 = 385.60/x
  3. Step 3: Cross multiply
    621.72x = 857.69 × 385.60
  4. Step 4: Simplify right side
    621.72x = 330,723.34
  5. Step 5: Solve for x
    x = 330,723.34/621.72
  6. Step 6: Final answer
    x = 531.95

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.